Reservoir systems, such as petroleum reservoirs, typically contain fluids such as water and a mixture of hydrocarbons such as oil and gas. To remove (“produce”) the hydrocarbons from the reservoir, different mechanisms can be utilized such as primary, secondary or tertiary processes. In a primary recovery process, hydrocarbons are displaced from a reservoir through the high natural differential pressure between the reservoir and the bottom-hole pressure within a wellbore. In order to increase the production life of the reservoir, secondary or tertiary recovery processes can be used (“enhanced oil recovery” or EOR). Secondary recovery processes include water or gas well injection, while tertiary methods are based on injecting additional chemical compounds into the well, such as surfactants/solvents and polymers, for additional recovery. The surfactants/solvents free oil trapped in the pores of the reservoir rock. In an enhanced oil recovery process, some of the chemical compounds that are injected will remain underground, and some of will be recovered with the oil that is produced.
There is a need for improved compositions, preparations, and methods for convenient and efficient EOR applications, particularly in high temperature reservoirs. There is also a need for methods for recycling/reuse of produced water and chemical compounds. The improved method employs coupling solvents commonly used in waterborne coating applications to increase oil recovery by taking advantage of their miscible and immiscible phase behavior in water as a function of temperature.